Biology is certainly a factor. BMR varies between individuals (even of the same weight and body composition). However it’s probably a smaller factor than the ge

Biology is certainly a factor. BMR varies between individuals (even of the same weight and body composition). However it’s probably a smaller factor than the genetic influence on hunger and satiety. And despite individual variation in BMR, I haven’t heard any evidence that some people have the ability to significantly ramp up their metabolism in response to consuming more calories.